1. Field of the Invention
The present invention relates generally to audio processing. More specifically, the present invention relates to controlling adaptivity of noise cancelation (i.e., noise cancellation) in an audio signal.
2. Related Art
Presently, there are many methods for reducing background noise in an adverse audio environment. Some audio devices that suppress noise utilize two or more microphones to receive an audio signal. Audio signals received by the microphones may be used in noise cancelation processing, which eliminates at least a portion of a noise component of a signal. Noise cancelation may be achieved by utilizing one or more spatial attributes derived from two or more microphone signals. In realistic scenarios, the spatial attributes of a wanted signal such as speech and an unwanted signal such as noise from the surroundings are usually different. Robustness of a noise reduction system can be adversely affected due to unanticipated variations of the spatial attributes for both wanted and unwanted signals. These unanticipated variations may result from variations in microphone sensitivity, variations in microphone positioning on audio devices, occlusion of one or more of the microphones, or movement of the device during normal usage. Accordingly, robust noise cancelation is needed that can adapt to various circumstances such as these.